As I no longer shoot film but wanted to scan some old slides (quite a few hundred of them) this amounted to a one-off need which was unlikely to be replicated. So, I bought a relatively cheap Asahi Pentax bellows outfit with a negative / slide holder (not all bellows outfits come with them). It cost about $100 AUD ($60 US). it had the advantage of being cheap, plus I already had an excellent lens for it (the SMC Takumar 55mm f1.8 - for which the bellows has marked settings) and a suitable camera (a Sony NEX camera.) The camera was a slight deficit in that it's a cropped sensor giving a restricted field of view which made capturing the full slides a little difficult - though it was not an insurmountable problem as it could be "fiddled with to minimise the cropping to the borders). Once set up, the process was VERY quick - drop a slide in then "click", drop the next slide in then "click" etc. You get the picture. Of course, some post processing was needed to deal with dust, scratches etc. which counts against this (some scanning software can deal with it automatically) but for those who have kept their slides in better condition than I, this is not such an issue. BTW for lighting I bought a cheap ($30 AUD) LED panel work light from a hardware store. (Worked perfectly.) The entire kit was mounted on a tripod with the panel light on a desk behind it. A further advantage is that the whole set up is quite small and can be stored in a desk drawer when not in use.
I am happy with the results though of course when viewed from a perspective of a film shot decades past but then viewed in a digital "today" there will always be some issues with sharpness etc in many images. But this is common to any method of scanning. For those who want a cheap means of scanning this is a good one providing good quality (not perfect due to technological considerations) at a cheap price and with acceptable results.
PS it almost goes without saying - shoot RAW so you have wider options in post.